move dummy onMakeFromFontData() into .cpp

It's borderline illegal to implement it there in the header with a
forward-declared SkFontData.  See also cl/314969840.

Change-Id: I81e981198014cce03fa9604aada5a383a847cfeb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/295640
Reviewed-by: 🤓Vy Nguyen <vyng@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>

Author: Mike Klein

modules/skparagraph/include/TypefaceFontProvider.h

@@ -67,9 +67,7 @@ class TypefaceFontProvider : public SkFontMgr {
                                            const SkFontArguments&) const override {
         return nullptr;
     }
-    sk_sp<SkTypeface> onMakeFromFontData(std::unique_ptr<SkFontData>) const override {
-        return nullptr;
-    }
+    sk_sp<SkTypeface> onMakeFromFontData(std::unique_ptr<SkFontData>) const override;
     sk_sp<SkTypeface> onMakeFromFile(const char path[], int ttcIndex) const override {
         return nullptr;
     }

modules/skparagraph/src/TypefaceFontProvider.cpp

@@ -24,6 +24,10 @@ SkFontStyleSet* TypefaceFontProvider::onMatchFamily(const char familyName[]) con
     return nullptr;
 }
 
+sk_sp<SkTypeface> TypefaceFontProvider::onMakeFromFontData(std::unique_ptr<SkFontData>) const {
+    return nullptr;
+}
+
 size_t TypefaceFontProvider::registerTypeface(sk_sp<SkTypeface> typeface) {
     if (typeface == nullptr) {
         return 0;